My first farm was 3 x 1.5L soda bottles mounted together according to V2 design, and with the modified airlift system.

It worked… but my plants(2 strawberry and a chili plant) didn’t survive my vacation.

So, if I hadto start the plants over, why notthe farm, too?

This new design is based on the same airlift as I know it works well. The bottles and mounting of them has been completely redesigned, though. I’m still using 1.5L soda bottles, but I cut them in two about midway down, wrap tape around the threaded end and a half-inch width along the cut to mask it for spraypainting.
As I don’t feel that 3 layers of white blocks enough light, I’m using gray primer first, then white paint on top of it.
To mark where to cut the bottles I made a simple rig of a couple of dowels mounted on a workbench with a whiteboard marker fastened to them with a rubber band. It works… sort of… (Not very accurate) For the next set of bottles I’ll have to find a tube that the bottles will fit snugly into, and use that as a template.

For suspension I’m using three lengths of thin chain and ’S’ hooks. On the edge of the bottles I’ve used a set of eyelet pliers to make holes and crimp into place eyelets for the hooks to hook onto.

In the neck of the bottles I’ve placed an ice-cream cup that I have perforated. Then it’s just a question of filling up with clay pellets and adding a plant. (for Norwegians; I’m using Henning Olsen Sjoko Kirsj, as sold in quad-packs. The ‘diet’ ice sold in the same sizes can also be used, but tastes awful in my opinion… )
The way the cups have been prepared is that I’ve cut off the rim, then holed the bottom with a small philips-head screwdriver that I heated with a ‘jet lighter’. You want the holes at least 2.5mm(0.1″) or more and probably  bit jagged around the edges or the surface tension in the water will keep it from draining through until a significant amount has gathered.

On the bottom bottle I’ve used a modified drinking cap from a water bottle(Imsdal if anyone in  Norway wonders)  where I removed the sliding plastic piece and ‘cored’ it with the biggest drill-bit I had(10mm). Then I glued in a piece of tubing using hot-glue.

Pros of this design:
It’s flexible as the bottles can be unhooked and moved up and down the chains.
This means I can have any number up to 5 on a single column, or dedicate one column to sprouts, and have a separate tank and nutrients more suited for young plants, and just move plants around as they mature.

Cons:
I may need to add tubes to more than just the bottom bottles, depending on the distance between the bottles and type of plant in them.

To do:
A better and more permanent fastening at the top. A single hook works… somewhat, but a hook for each chain will avoid the top bottle being disformed by the chains. Also, adding a second column.
This I plan to do by fastening a board at the top and screwing in hooks. 3 for the first chain, and 2 for the next, so that they form a somewhat elongated 5(as on a dice) so that the two columns share one chain.
A possibility is also to mount 6 hooks in a triangular pattern, with one in each corner, and one in the middle of each side, and hang 3 columns from those 6 chains. (all columns will be sharing two chains with the other columns) Then the airlift tubes can be ‘hidden’ in the middle of the design, too. A quad column with 8 chains is a possibility, but at least one column will get significantly less light than the others.

Also, while I have pictures, I find no way to post them here.